Question: $\dfrac{9}{10} - \dfrac{1}{3} = {?}$
Explanation: $ = {\dfrac{9 \times 3}{10 \times 3}} - {\dfrac{1 \times 10}{3 \times 10}} $ $ = {\dfrac{27}{30}} - {\dfrac{10}{30}} $ $ = \dfrac{{27} - {10}}{30} $ $ = \dfrac{17}{30}$